SEOUL, Jan. 3 (Yonhap) -- A prolonged cold spell sent the mercury plummeting nationwide on Thursday, with temperatures dropping to their lowest levels in decades, the country's weather agency said.

The South Korean capital city of Seoul recorded a temperature of minus 16.5 C in the morning, the lowest in 27 years since a minus 16.9 C was recorded in 1986, the Korea Meteorological Administration (KMA) said.

A cold wave watch for Seoul and its surrounding Gyeonggi Province, and a cold wave alert for the central part of the country have been issued, the agency said.

The morning low dropped to minus 24.3 C, the lowest temperature in the country, in Cheorwon, a mountainous town near the inter-Korean border, according to the KMA. Temperatures were recorded at minus 24.1 C in Paju, a border town in Gyeonggi Province, and minus 22.6 C in Chuncheon, Gangwon Province.

In Seoul, 136 injuries from falls were reported as of 8 a.m. Thursday, according to the Seoul Metropolitan Fire & Disaster Headquarters.

The low temperatures caused water pipes to freeze and burst across the country, including in Seoul where a total of 108 reports were filed overnight, it added.

The cold spell also hit North Korea, with the morning lows plunging to minus 22 C in some regions, according to the weather office.

Citizens in the North Korean capital city of Pyongyang saw the coldest weather with the morning low recorded at minus 19 C, the KMA said.

The severe cold weather was caused by a frigid continental high-pressure system and the chill from the northwestern region, the agency said.

The wave of exceptionally cold weather will continue and temperatures will remain lower than average all week, with morning lows in Seoul to hover around minus 14 C on Friday morning, it said.